Dual band omnidirectional antenna systems are useful for various wireless communications applications, particularly cellular infrastructure networks. Prior known dual band omnidirectional antenna arrays have been designed with two antenna arrays vertically stacked within a radome. Such vertically stacked arrays result in a long antenna. Other prior known dual band omnidirectional antennas, to reduce the overall length of a antenna, have two antennas arrays placed side-by-side within the same radome. Such side-by-side antenna arrays generally result in distorted radiation patterns for both bands in the azimuth plane due to interference effects that both antennas arrays experience from each other.